The present invention relates to a knockover roadway marking post. More particularly this invention concerns such a post which normally stands upright, but which can be knocked over and which will automatically return to its upright position.
A knockover marker post of the above-described general type is shown in German Pat. No. 1,277,292. This arrangement has a base that is fixed to the ground and an upper part that is urged by a spring against the base. The spring has one end secured to one of the elements, normally the base element, and another end secured to a cable that is looped through the upper element and secured at its free end to the base element again. The arrangement is so set up that when knocked over in the plane of the holding element constituted by the spring and cable this spring is compressed. Such compression urges the spring back into the upright position. Similarly when knocked over in a direction transverse to this plane the cable is pulled and the arrangement is once again biased back into the upright condition. When hit a glancing blow the device can, however, turn around and wind up the cable and spring so as to jam the arrangement in a position from which it cannot right itself. Furthermore this arrangement has the considerable disadvantage that it is relatively expensive to manufacture and difficult to install.
Another difficulty with the known knockover roadway marker posts is that they frequently do not right themselves in the exact position they were in before being knocked over. Thus a reflector mounted on the side of such a post and directed into the traffic is frequently improperly oriented after the post is knocked over. To this end such reflector posts are frequently made with circular bands of reflectors so that the angular orientation of the post relative to an upright axis becomes irrelevant. Such construction again increases overall costs, something which must be taken into account in an article of this type which must frequently be replaced, as after being knocked over a certain number of times it is inevitable that at least some of the marker posts will be permanently damaged.